Extruded modular panels with upstanding seam flanges as well as generally flat panels made of polycarbonate and other resins including fiberglass are widely used in the design of various architectural structures because they are a strong, lightweight alternative to traditional materials, like glass, which they often replace. For example, such modular glazing panels can be joined along flat panel edges or along upstanding seam flanges that extend along their edges to form glazing panel units that can be used either alone or with a supporting framework of, e.g., purlins or rafters, to form overhead, wall, or roofing structures. The ability of such panel units to transmit light has made them particularly useful where it is desired to allow sunlight to pass into a structure such as to illuminate an interior region of a building. An additional advantage of these panel units is that they have good energy conservation and sound insulation characteristics. The glazing panel units also have greater structural strength than single panels making them useful in applications where single panels could not be used or would require additional supporting structural elements.
The extruded modular panels with upstanding seam flanges as well as generally flat panels made of polycarbonate and other resins may be, e.g., up to 45 feet in length, 2-6 feet wide and typically are flexible. It therefore requires substantial skill and is time-consuming to assemble and install the panels into glazing panel units on-site. The challenge to assembling and installing the panel units faced by such skilled workers can be appreciated, for example, by examining FIGS. 1A and 1B which illustrate representative prior art panel pair assembly systems.
More particularly, FIG. 1A shows a purlin 1 and one of a series of metal retaining clips 2 spaced and affixed along the purlin. The retaining clips include horizontal flanges 3. Once the series of spaced retaining clips are in place on the purlin (or other supporting member), polycarbonate (or other resin) bottom modular panels 4A and 4B are manipulated into position and slid horizontally under the flanges of the retaining clips. Then, an elongated resilient batten joint connector 5 with a downwardly facing elongated bottom cavity 6A is forced down over the upstanding seam flanges 7A and 7B of modular panels 4A and 4B to lock them onto the retaining clips by way of sawteeth in the bottom cavity that mate with sawteeth on the flanges of the bottom panels. Finally, top modular panels 8A and 8B are manipulated into position with their seam flanges 9A and 9B aligned with the upwardly facing elongated top cavity 6B in the batten joining connector and pressed into place with the sawteeth of flanges 9A and 9B of modular panels 8A and 8B held in place by corresponding sawteeth within cavity 6B.
FIG. 1B shows juxtaposed panel units (or “insulated translucent sandwich panels”) 11 each comprising top and bottom generally flat fiberglass panels 13 and 15 with a grid made of up of vertically and/or horizontally disposed metal or resin grid members 19 (only one shown) located in the space between the panels and in abutment with the panels. The grid serves to, inter alia, maintain the spacing between the panels. The “fiberglass” from which panels 13 and 15 are made is a fiber-reinforced polymer made of a resin matrix reinforced by glass fibers. The resin used in the fiberglass may be a polyester, an epoxy, a thermosetting plastic or thermoplastic. Shelf supports 21 located at the top and bottom of the grid members are affixed to panels 13 and 15 by adhesive which is located in the interstices between the shelf members and the inner faces 23 and 25 of the top and bottom panels to form glazing panel units. Finally, adjacent insulated sandwich panel units are laterally attached using a clamp 27 comprising a bottom support 29 and a top support 31. In order to lock the adjacent sandwich panel units together, a screw 33 is passed through the bottom clamp support and screwed home in a receptacle 35 that projects downwardly from the top clamp support to lock down the clamp. The attachment of the grid to the panels as well as the onsite lateral attachment of adjacent sandwich panels, as in the case of the modular panels of FIG. 1A, is time-consuming and requires substantial skill.
While there are many known variations on the prior art panel unit systems of FIGS. 1A and 1B, they are indicative of the relative complexity of assembling and installing sloped glazing, skylights, roofs, walls and other architectural structures having paired panel units on-site.
The system of FIG. 1A also illustrates the conventional metal (retaining clip) to resin skin (flange of panel) contact employed in current modular upstanding seam panel retention systems. Because those skilled in this art have been wed to fixing the panels in place through such direct engagement of an unforgiving hard or high ultimate tensile strength metal retention clip against the resilient low ultimate tensile strength resin skin of the polycarbonate modular panel, it has been necessary to take extra steps to ensure that load specifications are met. For example, skin weight of modular panel flanges is greater than it otherwise would need to be in order to prevent cracking of the polycarbonate or other resin skin of the panel flanges under load. This excess weight results in unnecessary material usage/cost and reduced light transmission. Also, large numbers of closely spaced retention clips are often required to meet wind load and other load specifications by spreading out the load across more clips also to prevent cracking of the resin skin of the flanges under load, again leading to increased weight and material and labor waste.
FIG. 1C illustrates a prior art system which does not entail the use of prior prepared modular panel units. Rather, lower panels are fixed in place after which spacers are applied and top panels attached to the spacers. Most significantly, locking clips 714 must be located between the lower panels at regular intervals along the panels. Since the system does not include the metal armoring or cladding feature of the present invention, support members to which the clips are attached must be positioned at relatively close intervals to receive fasteners in the clips and support the panels.
There is therefore a great need for a system that makes it easier and less time-consuming to assemble and install or erect paired glazing panel units. If such a system also provided a completed architectural glazing structure comprised of glazing panel units made up of modular upstanding seam flange panels or flat resin panels which is safe, secure, strong and able to withstand substantially increased negative and positive wind and snow loads, a particularly unexpected and useful contribution to the art would be at hand. If such a system further eliminated the inherent limitations of conventional metal-to-resin engagement, required fewer retention clips, and made it possible to reduce panel thickness, an extremely important and unexpected advance in the art would be in the offing.
Present embodiments provide systems for readily assembling pairs of such glazing panels into glazing panel units either on-site (but typically in convenient ground level work areas) or off-site, and then readily installing the pre-assembled panel units on-site to erect the sloped glazing, skylights, roofs, walls, and other architectural structures.
These new systems are particularly elegant in that they armor or metal clad the standing seams of the modular panels and the flat panel edges to thereby provide a unique new retention that withstands increased wind and snow loads while making it possible to reduce the thickness and weight of the flat panels or the resin skin of the flanges of the modular panels and optionally to use thinner and lighter bottom or inner panels. These new systems are also surprisingly economical in terms of materials (e.g., the number of retention clips can be reduced and modular panels with thinner and hence less expensive resin skins and thinner flat resin panels can be used) and in terms of construction costs since they can be erected quickly and generally without special skills, and produce architectural structures that can accommodate longer spans, are surprisingly effective in limiting air, water and sound infiltration, and have outstanding energy conservation characteristics. Indeed, the present systems make it possible to readily insert infill into the airspace between the panels off-site (or on-site) in the form of translucent insulation (e.g., glass fiber), or to add metal screening to flat panel glazing units enhancing the fire resistance of the panel units and helping to resist severe localized impacts on the outer panels of the units. This is another welcome improvement since it is extremely difficult and expensive to add infill or metal grids to prior art panel units which must be assembled on-site.
Finally, it is important to accommodate horizontal expansion and contraction of the glazing panel units. While prior systems for assembling and installing panel pairs have a limited ability to accommodate such expansion and contraction, the use of the interlocking first and second locking engagement members of present embodiments accommodates such horizontal expansion and contraction far better than earlier designs and in a way not contemplated by those skilled in this art.